A novel modeling approach to predict the output performance of photovoltaic modules under different environmental conditionsKareem, Mohamed Saleem Abdul; Saravanan, Manimaran
doi: 10.1177/0037549718761208pmid: N/A
In this paper, an improved mathematical model of a single-diode photovoltaic (PV) module has been developed to predict the maximum power of the PV modules produced by different PV technologies, such as mono crystalline, multi crystalline, and thin film, under varying environmental conditions. The current–voltage characteristic equation of the PV module is used to extract the PV module’s unknown parameters, such as light generated current, saturation current, ideality factor, series resistance, and shunt resistance at standard test condition (STC). In the proposed PV model, numerical methods are used to calculate the parameters of the PV module at STC, by introducing new equations to estimate the value of series resistance and shunt resistance. By introducing new equations IMPP and VMPP, the maximum power of different PV modules manufactured by various PV technologies at different environmental conditions is then found. In the proposed PV model, the percentage relative error obtained at maximum power is calculated and the experimental results are compared with the models that exist in the literature for different PV modules. The maximum power obtained by the proposed PV model is much closer to that obtained by the Sandia model and Ishaque two-diode model. Furthermore, the output performance of the developed PV model has close agreement with the experimentally obtained data and it is verified practically.
New combined method for low energy consumption in Wireless Sensor Network applicationsChéour, Rym; Jmal, Mohamed Wassim; Abid, Mohamed
doi: 10.1177/0037549718759432pmid: N/A
Over the past few years the applications for Wireless Sensor Networks (WSNs) have grown at an ever-increasing rate. However, the evolution of those networks has been reduced by the energy scarcity. It retards the development of the WSN performances required while exploring new applications and improving the WSN potential. Besides, in order to design energy-efficient solutions, it is important to take into account the power dissipation due to noncompliance with time constraints. As a result, we will provide a model of power management that will be simulated and validated by the STORM Simulator (Simulation TOol for Real time Multiprocessor scheduling). However, unlike traditional WSN energy management systems, our power manager reduces the energy consumption through a dual approach: a global and dynamic approach using the analysis of the behavior of the network and a local one applied at the node level. We have relied on energy optimization techniques to yield extensive lifetime for every node battery and mainly both Dynamic Power Management and Dynamic Voltage and Frequency Scaling, which are appropriate for the WSN. This model will be based on a global Earliest Deadline First scheduling policy. Besides, we aim to extend the STORM simulation tool to include those power management techniques.
Modeling drivers’ speed choice on roads with complex shapes based on the curvature of the preview trajectoryXu, Jin; Zhao, Jun; Shao, Yiming
doi: 10.1177/0037549717751633pmid: N/A
The target speed needs to be determined based on the geometry of the road ahead and current operational state in order to realize automated driving along complex mountain roads. However, existing speed prediction and V85 models are unable to do so. This paper proposes a speed decision algorithm that is based on the curvature of the preview trajectory. Firstly, the trajectory point in each preview cross-section within the driver’s sight window is determined; the curvature of the preview trajectory is calculated and used as input data. Secondly, an objective function is selected to set the speed control pattern: minimum travel time; maximum comfort; minimum deviation from the reference speed; or multiple weighted objectives. Thirdly, the speed value for the preview cross-section is solved by optimizing the selected objective function. As the sight window rolls ahead, the target speed can be determined along the traveling distance. Because the trajectory generated within the boundary of the pavement is used by the driver, parameters such as the change in curve radius, deflection angle, lane width, and spiral length can change the driving boundary, which can change the trajectory characteristics and thus affect the target speed. Therefore, the proposed algorithm is able to determine the speed for roads with complex shapes. The field validation and simulation cases demonstrated that the target speed profile of different driving patterns can be obtained for different combinations of trajectory and speed patterns. Thus, the model can simulate diverse real-world driving behaviors and explain the diversity in driving speeds of different drivers.
Investigation of the effect of the sling angle and size on the reliability of lifting hooksOnur, Yusuf Aytaç
doi: 10.1177/0037549717744646pmid: N/A
The lifting hook is one of the vital components in material handling systems, since sudden accidents are unavoidable if the working reliability of the hook is poor. In this study, computer-aided single hook modeling is done in accordance with the DIN 15401 standard then extensive stress analyses at different sling sizes and angles and stress analyses when the hook is rigged by sling legs with unequal leg length and rigged by sling legs with unequal leg length and height have been conducted in order to reveal the effect of sling size and angle and different rigging manners on the safety factor of the lifting hook by using finite element simulation. Loads carried by each sling member are calculated and presented. Curved beam theory and simplified theory are employed to compare finite element simulation results. The critical sling angle at which the safety factor reduces evidently has been determined by altering the sling size and angle. The critical sling angle is found to be 51°, since reduction in the safety factor originates from a 51° sling angle.
Evaluating transportation infrastructure investment on a regional level: a system dynamics simulationWang, Zhong; Zhang, Yingying; Lian, Lian; Chu, Chenglong
doi: 10.1177/0037549717746750pmid: N/A
Transportation infrastructure investment (TII) has significant influence on regional economic development. This paper aims to measure the potential economic impact of TII and to help policymakers to evaluate different alternatives and strategies at the regional level through a system dynamics (SD) approach. First, an SD model is established to simulate the impact of TII on the economy and employment. The relationship between transportation investments and economic development is examined and the relevant employment and economic indicators are identified. Second, the variables, flow diagrams, and structural equations of the SD model are defined. Third, the program Vensim is employed to establish the SD model with economy, transportation, and employment subsystems. It is then calibrated based on the historical statistics data in Liaoning Province, China. Finally, scenario analysis of different transportation investment plans is presented. The results will help investors, policymakers, and government agencies to estimate the potential outcomes of proposed transportation investment plans and to further develop optimal policies for transportation investment.